defineSuite([
        'Core/Queue'
    ], function(
        Queue) {
    'use strict';

    var queue;
    beforeEach(function() {
        queue = new Queue();
    });

    it('can enqueue and dequeue items', function() {
        queue.enqueue(1);
        queue.enqueue('a');
        queue.enqueue(null);

        expect(queue.dequeue()).toEqual(1);
        expect(queue.dequeue()).toEqual('a');
        expect(queue.dequeue()).toEqual(null);
    });

    it('returns undefined when dequeueing while empty', function() {
        expect(queue.dequeue()).toBeUndefined();
    });

    it('updates length when enqueuing and dequeuing', function() {
        expect(queue.length).toEqual(0);

        queue.enqueue('a');
        expect(queue.length).toEqual(1);

        queue.dequeue();
        expect(queue.length).toEqual(0);
    });

    it('compacts underlying array', function() {
        var i;
        for (i = 0; i < 1000; i++) {
            queue.enqueue(i);
        }
        for (i = 0; i < 1000; i++) {
            queue.dequeue();
        }

        expect(queue._array.length).toBeLessThan(1000);
    });

    it('can peek at the item at the head of the queue', function() {
        queue.enqueue(1);
        queue.enqueue(2);

        expect(queue.peek()).toEqual(1);
        expect(queue.length).toEqual(2);
    });

    it('returns undefined when peeking while empty', function() {
        expect(queue.peek()).toBeUndefined();
    });

    it('can check if it contains an item', function() {
        queue.enqueue(1);

        expect(queue.contains(1)).toEqual(true);
        expect(queue.contains(2)).toEqual(false);
    });

    it('can clear items', function() {
        queue.enqueue(1);
        queue.enqueue(2);

        queue.clear();

        expect(queue.length).toEqual(0);
    });

    it('can sort items', function() {
        queue.enqueue(99);
        queue.enqueue(6);
        queue.enqueue(1);
        queue.enqueue(53);
        queue.enqueue(4);
        queue.enqueue(0);

        queue.dequeue(); //remove 99

        queue.sort(function(a, b) {
            return a - b;
        });

        expect(queue.dequeue()).toEqual(0);
        expect(queue.dequeue()).toEqual(1);
        expect(queue.dequeue()).toEqual(4);
        expect(queue.dequeue()).toEqual(6);
        expect(queue.dequeue()).toEqual(53);
    });
});
